21190523931 has 24 divisors (see below), whose sum is σ = 31573180080. Its totient is φ = 13685132736.

The previous prime is 21190523923. The next prime is 21190524001. The reversal of 21190523931 is 13932509112.

21190523931 is a `hidden beast` number, since 2 + 11 + 90 + 523 + 9 + 31 = 666.

It is not a de Polignac number, because 21190523931 - 2³ = 21190523923 is a prime.

It is a super-2 number, since 2×21190523931² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21190523831) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 62685 + ... + 215198.

It is an arithmetic number, because the mean of its divisors is an integer number (1315549170).

Almost surely, 2^21190523931 is an apocalyptic number.

21190523931 is a deficient number, since it is larger than the sum of its proper divisors (10382656149).

21190523931 is a wasteful number, since it uses less digits than its factorization.

21190523931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278155 (or 278152 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 36.

The spelling of 21190523931 in words is "twenty-one billion, one hundred ninety million, five hundred twenty-three thousand, nine hundred thirty-one".